2014•2015 faculteit industriËle … · upgrade of the motor test unit promotor : ing. eric...

2014•2015FACULTEIT INDUSTRIËLE INGENIEURSWETENSCHAPPENmaster in de industriële wetenschappen: energie

MasterproefUpgrade of the motor test unit

Promotor :ing. Eric CLAESEN

Promotor :ing. TIMO VAISANEN

Kevin Geutjens Scriptie ingediend tot het behalen van de graad van master in de industriëlewetenschappen: energie

Gezamenlijke opleiding Universiteit Hasselt en KU Leuven

2014•2015Faculteit Industriëleingenieurswetenschappenmaster in de industriële wetenschappen: energie

MasterproefUpgrade of the motor test unit

Promotor :ing. Eric CLAESEN

Promotor :ing. TIMO VAISANEN

Kevin Geutjens Scriptie ingediend tot het behalen van de graad van master in de industriëlewetenschappen: energie

Upgrade of the motor test unit

Hardware/software upgrade and supplying communication.

Master’s thesis

Automation Engineering

Spring 2015

Kevin Geutjens

Clarification of signature

ABSTRACT

HAMK Valkeakoski

Automation Engineering

Exchange studie

Author Kevin Geutjens Year 2015

Subject of Master’s thesis Upgrade of motor test unit

ABSTRACT

The purpose of this thesis was to complete an already started upgrade pro-

cess of the local didactical motor test unit. The new PC program has already

been written by a previous thesis, but lacks communication and is not com-

pletely finished. Also new hardware components have to be chosen and im-

plemented. Finally all these components have to be implemented and com-

missioned.

In order to achieve the communication to the PC, the old I/O panels will be

replaced by a new Beckhoff PLC, fitted with an Ethernet connection,

PROFINET connection and the necessary I/O terminals. In order to send

the necessary data to the PC program, the connection between the PC and

the PLC will be established with an Ethernet cable by using the TwinCAT

ADS Ethernet protocol. The old ABB frequency converter will also be re-

placed by a new ABB frequency converter, equipped with a PROFINET

interface. The communication between this frequency converter and PLC

will happen with a PROFINET connection.

The old hardware and software, as well as the new PC program made by the

previous thesis are well documented so these are very useful sources. Also

Beckhoff has a big online information system that I will use very often.

I have improved the previously made PC program and added the communi-

cation with the PLC to it. Also the PLC program itself is programmed in a

way it makes the setup much safer in use. The motor test unit is now again

fully operational and can be used by the students.

Keywords Motor, Beckhoff, ADS, PROFINET, C#.

Pages 59 p. + appendices 16 p.

ACKNOWLEDGEMENT

First of all I would like to thank a few people from HAMK university: Osmo Leiniainen

for helping me find components and showing me around in the automation lab the first

day I arrived, as well for showing me how the motor test unit initially worked. Timo

Väisänen as my supervisor, for all the help I received. Juha Sarkulla for giving initial

help to get my TwinCAT project started. Also a big thanks for Jan-Peter Novak, for do-

ing a great effort of ordering all the necessary Beckhoff components I needed for my

thesis. Further, many thanks go to all the other teachers and student in the Automation

department who made this thesis possible. A special thanks also goes to Annina Herala

for making this Erasmus+ project possible, and providing constant help in times of

need.

Next I would also like to thank my friends in Belgium Jori Winderickx and Steffen

Triekels, as well as my roommate Jan-Lennert Geuns for helping me figure out prob-

lems in the programming. I would like to thank all my family and friends (both in Bel-

gium and Finland) for supporting me.

Finally, a big thanks also goes to Petja Jantunen from the Beckhoff technical support for

providing quick and good support.

TABLE OF FIGURES

A Beckhoff PLC with the controller module and I/O modules [1]. ............... 2 The PLC scan cycle ........................................................................................ 3 Ladder diagram with A, B and C as inputs and X as an output. .................... 4 SFC program .................................................................................................. 5 Left: basic construction of a three-phase induction motor. [2] ; Right: more

efficient flat windings. [3] ................................................................................................ 6 Basic representation of a squirrel cage rotor[4] ............................................. 6 The stator magnetic field (top) caused by the 3-phase AC voltage (bottom) 7 Current-speed characteristic[5] and Torque-speed characteristic[5] .......... 8 Motor connections. Left: Star (Y) ; Right: Delta (Δ) ..................................... 9

Characteristics of the start-delta start. ...................................................... 10 Frequency converter with diode rectifier and IGBT inverter [6] ............. 11

Voltage waveforms in different stages of the drive [6] ............................ 11

IGBT inverter ........................................................................................... 12 Steady-state equivalent circuit of the induction motor [7] ....................... 12 Progress of the M-n characteristics curve by using V/f control. .............. 13 Stator voltage versus frequency profile using scalar control [7] .............. 13

Magnetic particle brake. [8] ..................................................................... 14 Simplified structure of an incremental encoder.[9] .................................. 14

Determination of the direction in quadrature output signals [10] ............ 15 RS422 differential line output for the A-channel. [10] ............................ 15

Wheatstone bridge of the strain gauges inside the load cell. [11] ............ 16 PROFINET communication channels ...................................................... 17 Complete setup ......................................................................................... 19

Motor unit with motor, mass, brake and encoder ..................................... 20

Motor nameplate ....................................................................................... 20 Left: Brake with load cell. Right: Occurring forces ................................. 21 Encoder ..................................................................................................... 21

Control unit ............................................................................................... 22 IO-panels .................................................................................................. 22

ABB ACS600 Frequency converter ......................................................... 23 The old windows 95 PC ........................................................................... 24 Original software “SIMO”........................................................................ 25 Top: old hardware layout. Bottom: new hardware layout. ....................... 29

Complete PLC configuration .................................................................... 30 Beckhoff CX9020 controller[15] ............................................................. 31 EL5101 channels and electrical layout. .................................................... 32

BK1250 terminal. ..................................................................................... 32 KL1408 channels and electrical layout .................................................... 33 KL2408 channels and electrical layout .................................................... 33 KL3064 terminal and electrical layout ..................................................... 34

Terminal KL3112 and KL3102 ................................................................ 35 KL4002 output terminal ........................................................................... 35 ABB ACS355 ........................................................................................... 36 Complete device configuration. ................................................................ 38 GVLs used in the PLC program ............................................................... 39

PPO type messages available for ACS355 drives .................................... 40 The separate bits in the status word and the control word........................ 41 PLC program layout ................................................................................. 42

I/O handling in the PLC program ............................................................. 43

Link between the flag variable and the linked I_O variable..................... 44 Connection monitoring ............................................................................. 45 SFC used for the direct starting mode ...................................................... 46 SFC for the star-delta starting mode ......................................................... 47

Function block to control the inverter. ..................................................... 48 ADS structure ........................................................................................... 49 ADS message ............................................................................................ 50 Class structure in the C# program ............................................................ 51 Layout of the main program ..................................................................... 54

Inverter start tab page ............................................................................... 55 Manual control screen .............................................................................. 56 Start-up chart ............................................................................................ 56 Acceleration chart ..................................................................................... 57

Characteristic chart ................................................................................... 57 Status bar .................................................................................................. 57 Completed motor test unit ........................................................................ 58

CONTENTS

1 ASSIGNMENT ........................................................................................................... 1

2 THEORETICAL BACKGROUND ............................................................................ 2

2.1 PLC...................................................................................................................... 2

2.1.1 Basics ....................................................................................................... 2 2.1.2 Scan cycle ................................................................................................ 2 2.1.3 Programming ........................................................................................... 4

2.2 Asynchronous electrical motor............................................................................ 6 2.2.1 Construction ............................................................................................ 6

2.2.2 Basic working principles ......................................................................... 7 2.2.3 Characteristics ......................................................................................... 8

2.2.4 Connection types ..................................................................................... 9

2.2.5 Direct online start (DOL) ........................................................................ 9 2.2.6 Star-delta start ........................................................................................ 10 2.2.7 Soft starter start ...................................................................................... 10

2.3 Frequency converter .......................................................................................... 10 2.3.1 Structure ................................................................................................ 10

2.3.2 Scalar control ......................................................................................... 12

2.4 Magnetic particle brake ..................................................................................... 14 2.5 Incremental encoder .......................................................................................... 14

2.5.1 Working principal .................................................................................. 14

2.5.2 RS422 TTL output ................................................................................. 15 2.6 Load cell and amplifier ..................................................................................... 16

2.7 PROFINET ........................................................................................................ 16

2.7.1 Network ................................................................................................. 16

2.7.2 PROFIdrive ............................................................................................ 17

3 INITIAL SITUATION .............................................................................................. 19

3.1 Setup .................................................................................................................. 19 3.2 Hardware ........................................................................................................... 20

3.2.1 Motor unit .............................................................................................. 20 3.2.2 Control unit ............................................................................................ 22 3.2.3 PC .......................................................................................................... 24

3.3 Software ............................................................................................................ 25 3.4 Functions ........................................................................................................... 26

3.5 Components requiring an upgrade .................................................................... 26

3.5.1 IO-Panels ............................................................................................... 26

3.5.2 Frequency converter .............................................................................. 27 3.5.3 Communication ..................................................................................... 27

4 NEW HARDWARE .................................................................................................. 29

4.1 Layout................................................................................................................ 29 4.2 PLC.................................................................................................................... 29

4.2.1 Replacing the old I/O panels ................................................................. 29 4.2.2 Configuration overview ......................................................................... 30 4.2.3 Controller ............................................................................................... 31 4.2.4 Encoder terminal EL5101 ...................................................................... 32 4.2.5 Bus coupler terminal BK1250 ............................................................... 32

4.2.6 Digital input terminal KL1408 .............................................................. 33

4.2.7 Digital output terminal KL2408 ............................................................ 33 4.2.8 Analog input terminal 0..10V KL3064 .................................................. 34 4.2.9 Analog input module 0..20 mA KL3112 ............................................... 34 4.2.10 Analog input module -10V…+10V KL3102 ........................................ 35

4.2.11 Analog output module 0..10V KL4002 ................................................. 35 4.3 Frequency converter .......................................................................................... 36

4.3.1 Usage ..................................................................................................... 36 4.3.2 Replacement .......................................................................................... 36 4.3.3 New drive .............................................................................................. 36

4.3.4 PROFINET communication .................................................................. 37 4.3.5 Modified parameters .............................................................................. 37

4.4 PC ...................................................................................................................... 37

5 PLC PROGRAM ....................................................................................................... 37

5.1 TwinCAT 3 ....................................................................................................... 37 5.1.1 eXtended Automation Engineering ....................................................... 37 5.1.2 eXtended Automation Runtime ............................................................. 37

5.2 Device configuration ......................................................................................... 38 5.2.1 Beckhoff PLC terminals ........................................................................ 38

5.2.2 PROFINET devices ............................................................................... 39 5.3 Global Variables Lists GVL .............................................................................. 39

5.4 PROFINET communication in TwinCAT 3 ..................................................... 40 5.4.1 PPO messages ........................................................................................ 40 5.4.2 Handling the status word and the control word. .................................... 41

5.5 Program layout .................................................................................................. 42

5.5.1 Main layout ............................................................................................ 42 5.5.2 Input and output handling ...................................................................... 43

5.6 Connection- and E-stop monitoring ................................................................. 44

5.6.1 E-stop monitoring .................................................................................. 44 5.6.2 Connection monitoring .......................................................................... 45

5.7 Datalogger ......................................................................................................... 45 5.8 Program selection .............................................................................................. 46

5.8.1 Direct start ............................................................................................. 46

5.8.2 Star-delta start ........................................................................................ 47 5.8.3 Soft starter start ...................................................................................... 47

5.8.4 Frequency converter start ...................................................................... 47 5.8.5 Motor characteristic ............................................................................... 48 5.8.6 Drive control (manual mode) ................................................................ 48

6 PC PROGRAM ......................................................................................................... 49

6.1 Existing.............................................................................................................. 49 6.2 PLC communication .......................................................................................... 49

6.2.1 TwinCAT ADS ...................................................................................... 49

6.2.2 Class structure ....................................................................................... 51 6.2.3 Connecting to the PLC .......................................................................... 51 6.2.4 Variable handles .................................................................................... 51 6.2.5 PLC-connection monitoring .................................................................. 52 6.2.6 Retrieving measured data ...................................................................... 52 6.2.7 Updating gauges .................................................................................... 53

6.3 Layout................................................................................................................ 54

6.3.1 Starting modes ....................................................................................... 55

6.3.2 Manual control ....................................................................................... 55 6.3.3 Charts ..................................................................................................... 56 6.3.4 Start-up chart ......................................................................................... 56 6.3.5 Acceleration chart .................................................................................. 57

6.3.6 Characteristics chart .............................................................................. 57 6.3.7 Status bar ............................................................................................... 57

7 CONCLUSION ......................................................................................................... 58

SOURCES ...................................................................................................................... 59

Appendix 1 Hardware list

Appendix 2 PLC IO table

Appendix 3 Electrical schematics

Appendix 4 Modified parameters ACS355

Upgrade of motor test unit

1

1 ASSIGNMENT

The goal of this thesis is to finish an upgrade process of the motor test unit

located in HAMK Valkeakoski. This machine is a didactical setup so stu-

dents can learn the characteristics of an engine depending on which way the

engine is started.

In 2012, two students already had this assignment for their thesis. One stu-

dent was responsible for upgrading the software on the PC, the other student

was responsible for communication. The software on the PC was finished,

but because the communication part was not made at all, the test unit was

far from finished. Also no new hardware has been installed so the system

was still equipped with the original hardware.

The test unit must be able to function with a new windows 7 PC at the end

of this thesis, and should keep functioning for at least 20 years. This means

some hardware components have to be upgraded. Secondly it also has to be

safer to use, which means the way an emergency stop is handled has to be

changed completely. At last it has to be student proof.


2

2 THEORETICAL BACKGROUND

2.1 PLC

2.1.1 Basics

A Programmable Logic Controller (PLC) is a programmable controlling de-

vice used for automation of (industrial) processes, such as factory assembly

lines, chemical processes or even amusement rides. The advantage of using

a PLC instead of a normal computer, is that a PLC can handle many in- and

outputs, and controls the system in real-time (chapter 2.1.2). Also both the

hardware and software of a PLC are optimized to operate in various condi-

tions. For instance, a PLC is usually immune to electrical noise, resistant

to vibration and impact, and can work in extended temperature ranges. Fur-

thermore, a PLC has a modular structure, with a “controller” module that

stores the program, and a wide range of in- and output modules that are

chosen depending on the process (Figure 1). The controller module is fitted

with non-volatile memory to stores the program for the PLC. This way the

program will still be kept even after performing a power cycle.

A Beckhoff PLC with the controller module and I/O modules [1].

2.1.2 Scan cycle

The main feature of a PLC is that it has real time control. This means when

an input value changes, the desired output responds within a desired period

so a process can be controlled. This reaction time can vary, for example a

temperature control requires a reaction time in the unit of seconds, while a

high speed process requires response within milliseconds.


3

In order to achieve this, a PLC uses the “scan cycle” (Figure 2). This cycle

continuously runs and takes only a few milliseconds depending on the pro-

gram. It consists of 3 basic steps: reading the inputs (A), executing the pro-

gram (B) and changing the outputs (C).

The first step is to read all the input values (also called periphery inputs) of

the modules that are connected to the PLC (A). These values are then stored

in the input memory of the controller, so the program can access these val-

ues. In order to make this process faster, the controller only updates the

changed input values. Input values that are the same as the previous cycle

are not written in the input memory again, since they are still in it. After this

the main program is executed once (B). By executing it once, it prevents the

program of being stuck in an infinite loop. The program reads the necessary

values from the input memory, and will change the desired output values if

needed. These output values are written in the output memory of the con-

troller. Finally all the changed output values in the output memory are trans-

ferred to the physical outputs (C) (periphery output). After this the control-

ler repeats this cycle.

The time it take to execute this complete cycle is called the “cycle time”,

and is a very important factor in automation processes. Because this cycle

is executed many times per second, usually only 1 or 2 input values will

change in one cycle. This results in a very low load on the program. In order

to keep a process real-time, a maximum cycle-time is determined. If the

cycle time exceeds this (e.g. program too long), damage can be caused to

the process since the controller cannot respond fast enough anymore to

changes. A watchdog can be implemented in the controller, checking this

time.

The PLC scan cycle


4

2.1.3 Programming

The PLC is programmed so it will perform the desired actions for the pro-

cess. It is done by writing the program on a PC, and sending this program

to the PLC. This program uses standard programming languages under the

IEC 61131-3 standard:

Ladder diagram (LD)

Structured text (ST)

Function block diagram (FBD)

Instruction list (IL)

Sequential function charts (SFC)

In this thesis LD, ST and SFC will be used.

The ladder diagram (Figure 3) is a method that can be compared to the old

relay racks. Each relay is represented by a symbol on the ladder diagram

with connections between devices. Figure 3 shows an example program. In

the upper network output X will be activated when both A and B are active.

The lower network shows an OR configuration of B and C, and an AND

configuration with A. Now X will only be activated when A will be active

in combination with B or C also being active.

Ladder diagram with A, B and C as inputs and X as an output.

Structured text is a textual programming language with the same syntax as

Pascal. An example of code is shown below, performing the same action as

Figure 3. VAR

A : BOOL;

B : BOOL;

C : BOOL;

X : BOOL;

END_VAR

X := A AND B;

X := A AND (B OR C);


5

Sequential function chart (Figure 4) is a graphical programming language

mostly used for sequential behaviour. It consists of 3 major components:

Steps, conditions and actions. A step contains several actions to be exe-

cuted. In order to go to the next step in the SFC, specified conditions must

be met. When the program advances to the next step, the current step is

deactivated and the next step is activated.

SFC program


6

2.2 Asynchronous electrical motor

2.2.1 Construction

An asynchronous induction motor is an electrical motor that uses electro-

magnetic induction to create torque on the output shaft. It consists of two

major parts: the stator (stationary) and the rotor (rotating). The stator is

connected to the three-phase AC power supply, and has no moving mechan-

ical parts. Compared to a DC-motor, this type of motor requires very little

maintenance since it requires no mechanical commutation.

The stator is the non-moving part of the motor and it has three pairs of wind-

ings, each pair rotated 60° relative to the previous pair (Figure 5). Every

pair is connected to one phase of the incoming three-phase AC voltage.

Connected, these windings will create a rotating magnetic field inside the

stator. In order to make this magnetic field more efficient flat winding are

used. These windings are protected by an aluminium or cast-iron housing

fitted with cooling fins on the outside.

Left: basic construction of a three-phase induction motor. [2] ; Right:

more efficient flat windings. [3]

Located in the inside of the stator, the rotor is responsible for transferring

the electrical energy of the stator to mechanical energy. The most common

type of rotor is the squirrel cage rotor (Figure 6), as it is very rugged and

reliable. It consists of longitudinal conductive bars that are connected to a

conducting “shorting” ring on each side. The bars are offset on a slight angle

in order to reduce the noise and vibrations.

Basic representation of a squirrel cage rotor[4]


7

2.2.2 Basic working principles

In order to create torque, the induction motor relies on the principle of elec-

tromagnetic induction. A rotating electromagnetic field is generated in the

stator (Figure 7), and passes through the rotor. Because the electromagnetic

field is moving, and the rotor is still not moving yet, the flux lines are inter-

secting with the bars of the rotor. According to the law of Faraday-Lenz (1),

this will create induced voltage inside the rotor bars.

𝐸 = 𝐵 ∗ 𝑙 ∗ 𝑣 (1)

This voltage will result in a flowing current following from the law of Ohm

(2).

𝐼 =

𝐸

𝑅𝑟𝑜𝑡𝑜𝑟

(2)

There is now a current flowing through the squirrel cage. If a conductor with

a flowing current is positioned in a magnetic field, this conductor will ex-

perience a force called the Lorentz force. The magnitude of this force can

be calculated using equation 3.

𝐹 = 𝐵 ∗ 𝐼 ∗ 𝑙 (3)

This force will cause a torque on the rotor and it will start to rotate. The

resulting rotational speed of the rotor is lower than the rotation speed of the

torque if the stator magnetic field crosses the rotor bars with a speed greater

than zero. This is the reason this kind of motor is called an asynchronous

motor. The difference in speed between the rotor and the stator magnetic

field is called the “slip”, and can be calculated by formula 4.

𝑠 =𝑛𝑠 − 𝑛𝑟

𝑛𝑠

(4)

The stator magnetic field (top) caused by the 3-phase AC voltage

(bottom)


8

2.2.3 Characteristics

A squirrel cage induction motor has several characteristics. Shown in Figure

8 is the current-speed characteristic. When the rotor is stationary, the current

flowing through the motor is maximal. Once the motor starts accelerating,

the current will decelerate. This can be explained by formula 5.

𝐼𝑠𝑡𝑎𝑡𝑜𝑟 =

𝑈 − 𝐵𝐸𝑀𝐹

𝑅𝑆𝑡𝑎𝑡𝑜𝑟

(5)

As explained in 2.2.2, a current is induced in the rotor bars when the motor

is rotating. This current induces a separate magnetic field in the rotor, which

causes a new (inversed) voltage in the stator. This inversed voltage is called

the back-EMF (BEMF). The BEMF will be 0V when the rotor is stationary,

since the magnetic field of the rotor does not cross the stator windings yet.

Once the rotor starts rotating, the BEMF will increase and the total voltage

over the stator windings will decrease. The decrease in voltage also means

a decrease in current according to Ohm’s law.

Current-speed characteristic[5] and Torque-speed characteristic[5]

Figure 8 shows the torque-speed (or torque-slip) characteristic of a 3-phase

squirrel cage induction motor. The nominal torque can be calculated using

formula 6. When the motor is turned on, a starting torque Tst is present. It is

about 1.5 times the nominal torque, and it is important that the load torque on

the motor is lower than the starting torque. If the load is higher than the start-

ing torque, the motor cannot start, and the high starting current will keep flow-

ing through the engine heating it up fast. Once the motor accelerates, it will

reach a maximal torque Tmax which is around 3 times the nominal torque. This

is also called the breakdown-torque and is located at around 80% of the syn-

chronous speed. After this point the torque will decrease to 0 as the speed

nears the synchronous speed. The nominal torque Tn is located a little bit to

the left of the synchronous speed. When the load on the motor increases, the

rotationspeed will decrease. This causes an increase of the torque created by

the motor axis an prevents it from stalling. When the load torque exceeds the

breakdown-torque Tmax , the motor will stall and stop.

𝑀𝑛 =

9.55 𝑥 𝑃𝑜𝑢𝑡

𝑛𝑛

(6)


9

2.2.4 Connection types

As explained in 2.2.1, the motor has three pairs of windings. Each pair has

its own letter: U, V or W. Each end of the windings is numbered one or two.

These windings can be connected to the 3-phase grid in 2 ways: star or delta

(Figure 9).

If a motor is connected in star (Figure 9, left), the line voltage UL will be

standing over two pairs of windings. Because of this, the voltage over 1 pair

of windings will be the phase voltage Uf (7). On the other hand, a motor

connected in delta configuration (Figure 9) has the full line voltage UL over

each pair of windings.

𝑈𝑓 =

𝑈𝐿

√3

(7)

Motor connections. Left: Star (Y) ; Right: Delta (Δ)

2.2.5 Direct online start (DOL)

When the motor is started using the DOL method, the motor is placed in the

desired configuration (star or delta) and directly connected to the grid. It is

the most common and simple method, but the starting current is very high.

It has the same value as the short circuit current which is about 7-14 times

the rated motor current. Because of this high current, this method does have

a high starting torque. Another disadvantage is that this puts a high mechan-

ical stress on the motor.


10

2.2.6 Star-delta start

This kind of start reduces the starting current and starting torque. The motor

is started using the star configuration. This reduces the voltage over the

windings, resulting in a lower starting current (33% of the DOL current)

and a lower starting torque (33%). When the motor is at full speed, the mo-

tor is rearranged to a delta configuration, providing full torque availability.

Figure 10 shows the characteristics of the star-delta start. The transition

from star to delta happens at 95% of the synchronous speed.

Characteristics of the start-delta start.

2.2.7 Soft starter start

A soft starter regulates the voltage over the motor to reduce the starting

current. It ramps up the voltage from initial voltage to max voltage. First,

the voltage is kept very low, in order to prevent sudden jerks. After that, the

voltage and the torque increases so the motor starts accelerating. This start-

ing type reduces the starting torque and mechanical stress on the motor.

2.3 Frequency converter

A frequency converter (“drive”) is a device that is used to control motors.

It converts the AC-input power to an AC-output power with frequency that

can be varied. The drive will change the output frequency to influence the

motor speed and –torque, in order to get the optimal characteristics for the

application it is used in.

2.3.1 Structure

Figure 11 shows the basic electrical structure of a frequency converter. The

schematic can be divided in 3 main parts: Rectifier circuit, DC link and in-

verter circuit. The input power (U1, V1, W1) will first be rectified to a DC

voltage. Next this DC-voltage will be converted back to AC power with the

desired (variable) frequency using an inverter circuit. The motor will be

connected to terminals U2, V2 and W2.


11

Frequency converter with diode rectifier and IGBT inverter [6]

Voltage waveforms in different stages of the drive [6]

The rectifier circuit is a three-phase bridge rectifier, which converts the

three-phase 380VAC input voltage to 520V DC-link voltage. It consists of

six diodes (two per phase) that will let the current pass in only one direction.

Next in the drive is the DC-link with a storage capacitor. This capacitor is

big enough so it can keep the voltage coming from the rectifier as constant

as possible. This allows the inverter to work very precise.

The next and final module in the structure is the inverter, the construction

of the IGBT inverter is show in Figure 13.


12

IGBT inverter

The IGBT inverter converts the DC voltage from the DC-link back into an

AC voltage with a variable frequency. It usually contains six IGBTs , from

which the top three chop the DC-voltage to the desired AC-voltage, and the

bottom three close the circuit so the current can flow.

2.3.2 Scalar control

A frequency converter has many options of controlling the speed and torque

from the motor. The simplest method – and also the one active in this thesis-

is the scalar control. Scalar control or open-loop control does not consider

the position of the rotor and the direction of the speed. It is most commonly

used in application where exact rotor precision is not needed and also does

not need help from an external position sensor on the rotor. The control is

purely done by changing the voltage and the frequency. As long as the mo-

tor does not exceed nominal speed, a fixed V/f ratio is maintained. For this

reason the scalar control is also called V/f control. A constant V/f ratio also

means that a constant flux in the stator is maintained, and can be found by

using the simplified steady-state equivalent circuit of the induction motor

(Figure 14). In this circuit we can assume that the stator resistance Rs is zero,

and that Ll is the combination of the leakage inductance of the stator and

rotor. Lm are the windings generating the stator flux.

Steady-state equivalent circuit of the induction motor [7]


13

Resulting from this equivalent circuit, we can retrieve equation 8.

𝐼𝑚 =

𝑉𝑠

2𝜋𝑓𝐿𝑚

(8)

Im is responsible for flux in the stator. Resulting from equation 8, keeping a

constant V/f ratio keeps the value of Im constant resulting in a constant sta-

tor flux.

Figure 15 shows the progress of the characteristics curve. By using a con-

stant V/f, the nominal torque moves to the right if the frequency increases.

Progress of the M-n characteristics curve by using V/f control.

However, at low frequencies (0-fc) a problem arises (Figure 16). Low fre-

quencies result in a low impedance of the stator windings, meaning that the

stator resistance can’t be neglected anymore. Because of this, the flux (and

resulting torque) would drop faster than wanted in V/f control. In order to

compensate this, an extra voltage compensation is added for low frequen-

cies. This compensation is called the I/R compensation, and can be easily

modified in the drive parameters. The region from fC until frated is the linear

V/f part. In this range a constant V/f ratio is maintained. When the speed set

point is set on the rated frequency frated, the voltage reaches its maximal

amplitude. Consequently, when the motor has to spin faster than the rated

speed, the voltage cannot increase. This causes the available torque to de-

crease (8).

Stator voltage versus frequency profile using scalar control [7]


14

2.4 Magnetic particle brake

In order to be able to apply an extra load to the motor axis, a brake is in-

stalled in the setup. The magnetic particle brake consists of a rotor con-

nected to the motor and a fixed housing (Figure 17). Between these compo-

nents a cavity is provided filled with magnetic particles. In the housing are

coils that can provide a magnetic flux through the brake. When there is no

electrical current, no magnetic field is created so the magnetic particles re-

main in the cavity. As a result there is no braking force. However when an

electrical current flows through the coils, a magnetic flux is created which

tries to bind the particles together [8]. The rotor tries to pass through these

bound particles, creating a resisting force on the rotor. The more current is

supplied, the stronger the particles will bind and the higher the braking force

will be. The advantage of this type of brakes is that the torque can be con-

troller very accurately, with an almost linear voltage to torque ratio.

Magnetic particle brake. [8]

2.5 Incremental encoder

2.5.1 Working principal

An incremental encoder generates pulses at a frequency proportional to the

rotational speed of the axis it is connected to. A spinning disk with radial

slits is connected to the input shaft and fixed slits are mounted to the housing

(Figure 18). On one side of the rotating disk LED’s shine light on the disk,

while on the other side photo transistors are mounted behind the fixed slits.

Every time the light can pass through a slit, a pulse is generated.

Simplified structure of an incremental encoder.[9]


15

Technically, only one LED/phototransistor pair is enough to measure the

rotational speed of the shaft. However, if also the direction of the rotation

is needed, an extra pair of LED/phototransistor is added, which is shifted

half a slit (90° electrical). Now one pair is the “A” pair, and the other is the

“B” pair. This configuration is called the “quadrature” configuration. If the

A pulse rises followed by the B pulse, the axis is rotating CW, while is the

B pulse rises before the A pulse the axis rotates CCW. This way both the

speed and direction can be determined. Usually, a third pair is added that

only gives 1 short pulse each full rotation. This is called the “0”, “C” or “Z”

pair.

Determination of the direction in quadrature output signals [10]

2.5.2 RS422 TTL output

The encoder used in this thesis has an RS422 TTL output signal. RS422 is

called a balanced differential line. Figure 20 shows this configuration for

the A-channel. A similar configuration is used for the B and 0 channels. The

differential line configuration creates a certain noise immunity, since the

receiver reads the difference between the A and /A signal. Common mode

noise will be actively cancelled out this way. The TTL outputs means that

the signal levels are generated using TTL logic. Resulting from this means

that the “high” level is a signal greater than 2.5V, and a “low” level is a

signal lower than 0.5V.

RS422 differential line output for the A-channel. [10]


16

2.6 Load cell and amplifier

A load cell is used to measure forces. It is a transducer whose electrical

signal is directly proportional to the measured force. The load cell in this

thesis is a strain gauge load cell.

The strain gauge load cell uses 4 strain gauges configured in a Wheatstone

bridge (Figure 21). An input (excitation) voltage is placed over two sides of

the bridge. When a force is applied, the resistance of the strain gauges will

change (two will increase, other two will decrease), resulting in a voltage

between the “signal +” and “signal –“ wires. However, the amplitude of this

signal is very low. The FSO of the used load cell is 2mV/V, which means

that when 10V excitation is applied, the signal difference between no load

and full load is only 20mV. This is not high enough, so before connecting

to the PLC, the signal needs to be amplified by an amplifier with the same

FSO as the load cell.

Wheatstone bridge of the strain gauges inside the load cell. [11]

2.7 PROFINET

2.7.1 Network

PROFINET is an Ethernet based Industrial Ethernet communication net-

work. It differs from normal Ethernet connections in that it can communi-

cate much faster and in real time. In order to do this PROFINET uses three

protocol levels (Figure 22):

TCP/IP level for normal IT services. Cycle is time around 100ms.

RT (Real Time) level. This is used for standard I/O systems and simple

drive solutions. Cycle time is around 10ms up to 1ms.

IRT (Isochronous real time). This is used for high speed applications

such as fast I/O systems or motion control. The cycle time here is up to

31.25 µs.

PROFINET RT uses cyclic data exchange, which means that data is ex-

changed between controller and device in a predefined cycle time. In order

to achieve this cycle time, RT data is prioritized over standard Ethernet data.


17

PROFINET communication channels

2.7.2 PROFIdrive

PROFINET exchanges data transparently by default. The received or sent

data has to be interpreted by the user in the PLC or PC solution. In order to

make communication easier, application profiles for PROFINET were de-

veloped. These are joint specifications concerning certain properties, per-

formance characteristics and behaviour of devices and systems that are de-

veloped by manufacturers and users [12]. Generally, there are two different

types of profiles:

General application profiles

These can be used for different examples, such as PROFIsafe for im-

plementation of functional safety, or PROFIenergy for low energy ap-

plications.

Specific application profiles

These are developed for specific types of applications, such as

PROFIdrive, which is a profile specifically made for communication

with drives.

As mentioned above, communication between the PLC and the drive will

happen using the PROFIdrive application profile. This way the communi-

cation happens in the most efficient way, with minimal cycle times and easy

control of the drive.


18


19

3 INITIAL SITUATION

3.1 Setup

Complete setup

The test unit contains three groups of components: motor unit, control unit

and PC with communication. The motor and brake are both controlled by

the main control unit. This control unit in its turn communicates with the

PC through old parallel connections.

Depending on what the user clicks on the PC, the control unit will execute

the demanded tasks and send back all measured data necessary for the PC.

Chapter 3.4 contains more detailed information about the functions.

The complete setup was made as a thesis in the year 2000 by a Finnish stu-

dent called Osmo Vuotila. His thesis has been written completely in Finn-

ish, which made it very hard to get information about the working princi-

ples, since this thesis was made by an exchange student who cannot speak

Finnish.


20

3.2 Hardware

3.2.1 Motor unit

Motor unit with motor, mass, brake and encoder

Motor (A) The biggest and main part of the motor unit is the motor itself. It is a 1.75kW

three-phase asynchronous induction motor from ABB. It is controlled by

the ABB ACS600 frequency converter in the control unit, and is mechani-

cally connected to a mass that acts as the load.

Motor nameplate

Brake (B)

On the other end of the mass a magnetic particle brake is connected. The

brake is a Lenze type 04 and has a maximum braking torque of 40Nm. It is

used primarily for testing the overall power-to-slip characteristic from the

motor, but can also be manually operated with the PC. It is controlled by a

0-10VDC analogue signal coming from the control panel, where 0V is no

braking power and 10V is maximum braking power. The temperature of the

brake is measured by a PT-100 resistor inserted into the brake.[13]

A B

C

D


21

Load cell (C)

The braking force is measured by a load cell, mounted as shown below. If

the brake starts applying more force, it will put more pressure on the load

cell, so the force on the load cell is a unit for the applied braking force.

Left: Brake with load cell. Right: Occurring forces

Encoder (D)

Speed measurement is done with the incremental encoder. It is made by

Kübler (type 5820-1541-5000) and has a pulse rate of 5000 pulses/revolu-

tion. Communication is established by an RS-422 connection to the control

unit. Here the I/O panel measures the time between 2 pulses to measure the

rotation speed of the motor. Direction is not measured.

Encoder

Floadcell Tbrake

Floadcell = force seen by the load cell

Tbrake = the torque caused by the motor brake


22

3.2.2 Control unit

Control unit

The control unit is the heart of the setup. In this part all the components of

the motor unit are controlled, information about current, power and

rotationspeed is gathered and send to the PC.

Analog IO-panel (A), digital input panel (B), digital output panel(C)

All of the signals coming from and going to the components in the control

unit and motor unit are connected to these panels. Each panel is connected

to the PC with his own parallel interface, and because of this it will be im-

possible to connect it to a modern PC. Therefore the panels have to be re-

placed by new components so a connection to a PC can be established.

IO-panels

A

D

E

F

G

H

B C


23

Frequency converter (D)

The frequency converter is an ACS600 from ABB, and is also equipped

with digital and analog inputs and outputs. These IO’s are used to control

the motor when the manual frequency converter mode is active, and is the

only way of communication. The frequency converter also returns its own

measured current as well as power consumed by the motor. There are no

possibilities to use any Ethernet or bus-connection to communicate with it.

Because of the lack of communication possibilities and the overall age of

the frequency converter, it has been decided to replace it by a new one in

this thesis.

ABB ACS600 Frequency converter

Power amplifier and transducer (E)

The output current of the IO-panels is not sufficient to power the brake, so

an amplifier is placed between the brake and the IO-panel. The amplifier

has an input voltage of 0-10VDC and output voltage of 0-24VDC/1A.

The transducer converts the small voltages coming from the load cell to a

measurable voltage for the IO-panel.


24

24VDC power supply (F)

This 24VDC power supply provides 24VDC to all the components that need

a 24V supply/signal. It has a maximum output current of 5A.

Contactors (G)

Because the outputs of the IO-panels do not provide enough voltage or cur-

rent, contactors are used to connect various parts of the control unit and

motor unit to the 230/400V lines. They are controlled by the digital output

panel.

The soft starter is located on the far left of the contactors, and is used when

the program is in “soft start mode”.

Main contactor

This contactor supplies the main voltage to the whole system. It is connected

to the emergency stop, so when the emergency stop is activated, the com-

plete system loses power.

3.2.3 PC

The old windows 95 PC

The PC is an outdated Windows 95 desktop with 192 MB of RAM and a

400MHz Intel Pentium II processor. It communicates with the control unit

by 3 separate parallel interfaces. It will be replaced by a new PC with the

Windows 7 operating system.


25

3.3 Software

There are 2 versions of the software: the original (working) software run-

ning on the Windows 95 PC, and the new version made by Vincent Peer-

linck in 2012. [14]

The original software is called “SIMO” and is currently still being used by

the students. The main problem with this software is that it only works on

the old computer, and will not be able to communicate with the new hard-

ware that will be installed. For this reason new software has already been

developed.

Original software “SIMO”

This new version of the software is fully working, but has no ways of com-

municating with the hardware. It has been developed in Microsoft Visual

Studio 2010 using C# and works on Windows 7 and newer. An important

part of this thesis is to complete this software by implementing communi-

cation between the PC and the hardware.


26

3.4 Functions

The current software has seven different modes:

Direct start

Star-delta start

Start with soft starter

Start with frequency converter

Power-to-slip characteristic

Manual mode

Brake temperature gauge

By clicking the start button in the first four modes, the motor will be started

accordingly to the selected mode. Meanwhile the current through the engine

is being measured and stored. After a few seconds the motor is disconnected

again and the program will show the current that has been flowing through

the engine in function of the time. This way students can compare the dif-

ference in the starting modes, and the difference in start-up current.

When the power-to-slip characteristic mode is activated, the motor starts

and the brake will gradually increase torque until the motor stops. After that

the brake releases and the motor is disconnected. Students can then see the

power/slip characteristic on the screen.

In manual mode the students can control the motor speed, direction and

brake torque. The speed and direction are both controlled by the frequency

converter. The temperature of the brake gauge can be seen on the screen

when the last mode is activated.

3.5 Components requiring an upgrade

3.5.1 IO-Panels

Firstly, all of the IO-panels are connected to an old parallel interface to the

PC. The digital input and output panels are connected directly to the moth-

erboard of the old PC. If the PC will be upgraded, it will be impossible to

connect these. Secondly, all of the hardware components are directly oper-

ated by the program of the PC. This means that the PC sends the signals to

all of the hardware components separately. The disadvantage of this is that

when the PC crashes there is no control of the hardware components any-

more, which can sometimes lead to dangerous situations. Resulting from all

these arguments, it has been decided to upgrade/replace the IO-panels.


27

3.5.2 Frequency converter

The currently installed frequency converter is made in 1999. It is very bulky

in size and has no options of communication installed. Because of this, pa-

rameters of the frequency converter could only be modified by using the

operator panel located on the frequency converter. In order to gain more

flexibility, and to make sure this test unit will still work after 20 years, it

has been decided to replace the frequency converter as well.

3.5.3 Communication

Following from the decisions of upgrading the IO-panels and frequency

converter, a new way of communication is also needed. One of the goals is

to make the system more flexible, so instead of using separate hardwired

connections between the PC, PLC and frequency converter, a communica-

tion protocol will be used. This way they will be easily replaceable in case

of a failure, and it will be very easy to expand the setup as well. Which types

of communication is used will be explained later in the thesis.


28


29

4 NEW HARDWARE

4.1 Layout

Since the old system used very old parallel connections to the PC and analog

signals to control the frequency converter, it has been decided to change

these connections and make them easier and more flexible. In Figure 33 the

top diagram represents the old layout. The bottom diagram is the new lay-

out, which uses an independent PLC. This PLC communicates with the new

PC using an Ethernet connection and communicates with the new inverter

by using a PROFINET connection. It is already clear that the new layout is

much easier to implement and maintain.

Top: old hardware layout. Bottom: new hardware layout.

4.2 PLC

4.2.1 Replacing the old I/O panels

As mentioned in “3.5.1 IO-Panels”, the IO-panels were connected to the PC

using old parallel connections. Also, the panels only converted signals to

and from the PC. There was no intelligence present in the panels, which

means that all of the hardware components were directly operated by the

program of the PC. The disadvantage of this was that when the PC crashed

there was no control of the hardware components anymore, which could

sometimes lead to dangerous situations. In order to achieve a safer and more

reliable system, a form of intelligence needs to be added between the PC

and the hardware components.


30

In order to gain this intelligence, a PLC will be added between the PC and

the hardware, replacing the IO-panels. It will be in control of all the hard-

ware components, and retrieve all data from the mounted sensors. Also,

communication with the new frequency converter will be managed by this

PLC through PROFINET.

4.2.2 Configuration overview

Beckhoff has a modular I/O terminal system, which makes it easy to re-

place, add and remove I/O terminals. Every bus terminal can communicate

with the controller through a build-in bus that is directly integrated in the

bus terminal. Every terminal that is added is automatically connected to this

bus. Depending on the name of the bus terminal the terminal has the K-bus

(KLxxxx) or the Ethercat-bus (ELxxxx). Both types are incompatible with

each other, and need a coupler to transfer data from one bus to another. It is

only possible to transfer from the E-bus to the K-bus. Once the coupler from

E- to K-bus is inserted, you cannot put a coupler after it to transfer to the E-

bus. Thus all the E-bus terminals must be placed, followed by an E- to K-

bus coupler and then all the K-bus terminals must be placed.

Complete PLC configuration

The complete PLC configuration is shown in Figure 34. The first element

is the controller with the Ethernet and PROFIBUS ports. Following is the

EL5101 encoder interface. This is the only E-bus terminal, so this is fol-

lowed by a BK1250 coupler terminal so all the K-bus terminals can be con-

nected. The next element is the KL1408 digital input terminal, followed by

two KL2408 digital output terminals KL2408. The four next terminals are

dedicated to analog signals: 0-10V input (KL3064), 0..20mA input

(KL3112), -10..+10V analogue input (KL3102) and 0..10V analogue out-

put (KL4002). The final terminal is the KL9010 end terminal.


31

4.2.3 Controller

Many projects in HAMK use the local PC to both program and run the PLC

program. This PC is used as the controller and is connected to a bus coupler

to communicate with the I/O Beckhoff terminals. The main problem with

this method is that when the PC is turned off or crashes, the control over the

I/O terminals is also lost, as the connection between the PC and terminals

is lost. In order to make sure the control over the motor will be maintained

at any time, a dedicated controller will be used instead of a PC. This way

the controller can still maintain control over all the hardware components

when the PC is turned off or crashes.

The controller is a Beckhoff CX9020-0110-M930. This controller is

equipped with its own CPU and integrated TwinCAT 3 runtime, so it does

not need another PC to operate. It is also equipped with two RJ45 Ethernet

interfaces, from which one will be used to connect the PLC to the PC and

send the necessary data. This will also be used to program the PLC. Next,

there are also 2 RJ45 PROFINET RT controller interfaces (option M930).

One of these interfaces will be used to establish PROFINET communication

between the ABB frequency converter and the PLC. The controller also has

4 USB 2.0 interfaces and a DVI connection (screen). These will not be used,

but can be used for later projects or when this test unit will need future up-

grades. Right next to the CPU module is the power supply terminal for the

electrical connections.[15] This module requires 24V DC power supply,

which is already present in the current electrical setup of the motor test unit.

Figure 35 shows a CX9020 controller. The controller in the project has two

PROFINET interfaces instead of the RS485 interface shown in the picture.

Beckhoff CX9020 controller[15]

On the right side of the controller different I/O busterminals of Beckhoff

can be added. The CX9020 controller has an E-bus, so first all the ELxxxx

components must be inserted.


32

4.2.4 Encoder terminal EL5101

The encoder used in this thesis has RS422 TTL output signals. In order to

be able to read these signals, this specific encoder interface terminal is re-

quired. It is able to read all the input signals, and provide 24V power input

to the encoder. The E-bus version (EL5101) of this interface terminal has

been chosen, since the delivery time was only a few days, compared to 2

weeks with the K-bus version (KL5101). As explained in chapter 4.2.2, the

first elements in the system must be the Ethercat busterminals, so this ter-

minal is mounted first next to the controller.

EL5101 channels and electrical layout.

4.2.5 Bus coupler terminal BK1250

All of the next terminals in the configuration will be K-bus terminals, since

HAMK Valkeakoski has a big stock of these. In order to transfer from the

E-bus to the K-bus, this buscoupler is required (Figure 37). This terminal

connects the E-bus to the K-bus terminals. It also needs its own power

source (24VDC) in order to be able to operate. After this terminal up to 64

extra terminals (K-bus) can be added to the system.

BK1250 terminal.


33

4.2.6 Digital input terminal KL1408

Because the testing unit has three fuses and an emergency stop, digital in-

puts are required. The KL1408 digital input terminal acquires binary data

from the system and sends it to the controller. It has eight input channels

which is double of what is necessary. This is done to be able to expand, and

because these were already available in HAMK. Each input channel is

equipped with an indication LED so it is easy to see if a channel gets an

input or not. Also, every input signal is electrically isolated from the con-

troller, since it has an opto-coupler for each channel.

KL1408 channels and electrical layout

4.2.7 Digital output terminal KL2408

There are 2 digital output terminals present in the system. Each KL2408 has

8 digital outputs that are electrically isolated from the controller. All the

relays that are in the system, are controlled by these terminals.

KL2408 channels and electrical layout


34

4.2.8 Analog input terminal 0..10V KL3064

This analogue input terminal measures an input value ranging from 0V to

10V DC. The voltage gets digitized to a resolution of 12 bits and is trans-

mitted to the controller. It takes approximately 4ms to convert the value,

which is by far fast enough for the application it has to measure. It is con-

nected to the pt100 converter module from Dataxel, which gives 0V and

0°C, and 10V and 300°C.

KL3064 terminal and electrical layout

4.2.9 Analog input module 0..20 mA KL3112

The KL3112 analogue input module measures signals in the range of 0 to

20mA and converts it into a 15bit number. It uses a differential input, which

means the circuit of the signal is electrically floating with respect to a

ground reference. This means the sensor to connect usually has 2 signal

cables (+ and -) and 1 ground cable.

However, a number of problems occurred while using this analogue input

together with the sensor:

First of all the ammeter it is connected with has a 0..20mA single ended

output (2-wire), while the analogue module uses differential inputs (3-

wire). This problem has been solved by connecting the signal wire of

the sensor into the “+input 1” side of the terminal (Figure 41). In order

to now mimic a differential signal, the “-input 1“ side got connected to

the “Ground” side, which in its turn is connected to the 0V signal of the

sensor. This way the single ended output signal is connected to a differ-

ential input.

Secondly, this terminal takes 140ms to convert an analogue input value

to a number. This is way too slow, since the motor only needs 400ms

to go from 0 to nominal speed when directly started. This would result

in only 3 samples, which is insufficient. In order to make this terminal

faster, it had to be configured in TwinCAT using the build in registers.

It has now been configured to only take 10ms to convert an input value.

Resulting in much more samples when the motor started, this gave a

much better and smoother graphic.


35

Terminal KL3112 and KL3102

4.2.10 Analog input module -10V…+10V KL3102

Because the force sensor in this setup has an output signal of -10V to +10V,

this terminal is necessary to measure the braking force. Just like the KL3112

module, this module also has differential inputs (Figure 41). It has a resolu-

tion of 16 bit, and needs 140ms to sample. This sample rate is not fast

enough, so it has been configured to be 10ms. Also, the output signals of

the sensor are single ended, so the “-Input 1” terminal got connected to the

“Ground” terminal in order to mimic a differential signal.

4.2.11 Analog output module 0..10V KL4002

The final I/O terminal is used to control the magnetic particle brake in the

unit. It has an output voltage of 0V to 10V, with a 12bit resolution.

KL4002 output terminal


36

4.3 Frequency converter

4.3.1 Usage

The frequency converter (or “drive”) is used to give students more control

over the motor, and to show the influence on the starting current when start-

ing using this drive. When the manual program mode is selected, students

can manually control the speed and direction of the motor.

4.3.2 Replacement

In the old system an ABB ACS600 drive was used. It was controlled by

electrically connecting analog and digital inputs of the drive to analog and

digital outputs on the old IO cards. Also speed and current of the motor was

transmitted from the drive to the IO cards by electrical connections. In other

words, the communication between drive and PC was very complex.

In order to simplify the communication, it was decided to use

communication through some kind of bus or ethernet protocol. The old

drive had none of these capabilities. Adding that the drive was already 15

years old lead to the decision to replace it by a new drive fitted with

communication possibilities.

4.3.3 New drive

The new drive had to be cheap, yet student proof and had to be able to use

PROFINET communication. According to T.Väisänen, ABB drives of the

ACS355 series were very cheap yet good. HAMK already had more than

10 of those drive for students to learn with. Also, this drive can fit an extra

module for PROFINET communication. Resulting from this was an ABB

ACS355 drive for motors with 2.2kW nominal power. This is higher than

the 1.75kW motor that is installed in the system, in order to make it more

“student proof”. An optional FENA-11 PROFINET module is fitted to the

drive, so it can use PROFINET communication with the controller.

ABB ACS355


37

4.3.4 PROFINET communication

In order for the drive to be able to communicate by PROFInet, an additional

adapter had to be ordered. In this case FENA-11 adapter for ABB ACS355

drives has been chosen. It has 1 RJ-45 Ethernet port, and supports

PROFINET, Modbus TCP and normal Ethernet/IP.

4.3.5 Modified parameters

For the drive to be able to work with the PLC, a number of parameters had

to be changed. The list (and order) of the parameters to be modified can be

found in appendix 3.

4.4 PC

The main starting point of the thesis was that the computer had to be up-

graded. The new PC is a standard desktop with 1 RJ-45 Ethernet port that

will be used to connect to the PLC. It has a 3.3 GHz quad-core processor

and 16GB of RAM. The operating system is Windows 7.

5 PLC PROGRAM

5.1 TwinCAT 3

5.1.1 eXtended Automation Engineering

TwinCAT 3 XAE is PC based programming software for Beckhoff prod-

ucts. It integrates in the Microsoft Visual Studio 2013 environment in order

to provide the user with an expandable and future-proof environment.

5.1.2 eXtended Automation Runtime

The TwinCAT 3 Runtime is an environment where the TwinCAT modules

can be loaded, executed and administrated. The CX9020 controller in the

system has this runtime installed, so this controller is able to run the pro-

gram and configure all the IO-terminals that are connected to it.


38

5.2 Device configuration

In order for the controller to be able exchange data with the IO-terminals, a

device configuration has to be generated (Figure 44). This device configu-

ration describes all the hardware that is connected to the controller, includ-

ing the build-in memory of the controller. Also, all the terminals can be

configured here and variables can be connected to physical inputs and out-

puts on the terminals.

Complete device configuration.

5.2.1 Beckhoff PLC terminals

The first device in Figure 44 is the CX9020 controller. It shows “inputs”

and “outputs”, which are used for getting basic information about the con-

troller. The first device under the CX9020 is the EL5101 terminal, which is

connected to the Ethercat bus of the controller (EK1200).The next terminal

is the bus coupler, which has all the K-bus terminals connected to it. Now,

every terminal can be configured separately and the variables used in the

program are assigned to the correct in- or outputs channels from the correct

terminal.


39

5.2.2 PROFINET devices

Because the CX9020 is fitted with 2 PROFINET ports, the devices con-

nected to PROFINET should also be added in the configuration. These de-

vices are shown under “PROFINET port” (Figure 44), and can be found

automatically by letting the controller scan the network. In this case the

ABB ACS355 drive is connected to the network and added in the device

configuration. Now all the PROFINET parameters can be configured. 5.4

will explain the configuration and handling of the PROFINET communica-

tion in TwinCAT more detailed.

5.3 Global Variables Lists GVL

A global variables list (GVL) is a list of variables that are accessible regard-

less of the part of the program. All of the variables that are used in the pro-

gram are put in global variable lists in order to make the program as flexible

as possible. In order to gain clear overview of the variables, 4 different

GVL’s are used in this thesis (Figure 45):

I_O: This list only contains variables that are connected to physical in-

or outputs. This is done in order to get a clear overview of what goes

out and what stays inside the PLC.

Flags: All of the variables that only stay inside of the program and are

not connected to any output signal (both physical and Ethernet) are lo-

cated in this list. Also, when any binary (contactor) output value needs

to be changed, the program changes values in this GVL. Only the last

step in the program transfers the variables from this GVL to the corre-

sponding flags in the I_O GVL. This way full control and overview

over the outputs is constantly maintained.

PC_Variables: The variables that are exchanged with the PC program

through the Ethernet connection can be found here.

PROFINET: Since the PROFINET communication requires a lot of

variables, a separate GVL is made containing these.

GVLs used in the PLC program


40

5.4 PROFINET communication in TwinCAT 3

5.4.1 PPO messages

As mentioned in chapter 3.6.2, we will use the PROFIdrive profile to com-

municate with the drive. In order to accomplish this, a “PPO” message type

has to be chosen. PPO is a “Parameter/Process data object”, and determines

how data will be exchanged between the drive and the controller.

Because PROFIdrive uses PROFINET RT, every cycle a PPO message will

be sent from the drive to the controller and vice versa. The speed at which

this happens is determined by the chosen cycle time. A PPO message con-

sists of two fixed data words, followed by a number of data words contain-

ing process data (PZD) (Figure 46). The amount of PZD words depend in

the PPO type that has been chosen. In this thesis PPO type 4 will be used,

meaning that two fixed data words and four PZD words will be exchanged

between controller and drive.

PPO type messages available for ACS355 drives

The two fixed data words in the message sent from the controller to the

drive consist of a “Control Word” (CW) and a “Reference Value” (REF).

The control word contains various bits that can control the status of the mo-

tor e.g. you can start and stop the motor by changing the corresponding bit

in the CW. The REF is used to control the speed of the motor. The way this

REF value is handled can be parametrised in the drive. The four PZD values

contain data that has to be written to certain parameters. Which parameters

are affected are chosen in the drive parameters.


41

In the message sent from the controller to the drive, the 2 fixed data words

now contains a “Status Word” (STW) and an “Actual Value” (ACT). The

status word contains bits that give information about the state of the drive

e.g. if the drive is active or stopped. The ACT word contains the current

rotational speed of the motor. This value is used in the program to show the

motor speed on the screen. Next, the four PZD values can contain infor-

mation about the current speed of the motor, the current flowing through the

motor, drive temperature… . The information that is transmitted through

these words can be parametrised.

5.4.2 Handling the status word and the control word.

As mentioned in 5.4.1, the status word and control word consist of separate

bits with each its own function. Inside of the PROFINET GVL, the variables

for the status word and the control word are located, as well as their separate

bits (Figure 47). By doing this, every bit is easily accessible, making it very

easy to control the motor and get the status of the drive.

The separate bits in the status word and the control word.


42

5.5 Program layout

5.5.1 Main layout

The main layout of the PLC program is shown in Figure 48. The PC sends

information about the selected starting mode to the PLC. A matching func-

tion block is loaded depending on the selected mode. Next when the user

gives the command to start the measurement, the datalogger is started to

measure all necessary data, and the motor starts according to the selected

mode by controlling the needed contactors. After the measurement is done,

the datalogger sends an array back to the PC containing all the measured

data during the measurement. When manual mode is selected, full drive

control is possible by the user, and the PC will constantly receive updates

about the input values of the PLC. Another key feature is the constant con-

nection monitoring. The PLC constantly gets polling signals from the PC,

and when these disappear (e.g. cable unplugged) the E-stop is triggered.

When this happens all of the outputs are overridden in such a way the ma-

chine goes to a safe state. When the E-stop is not active, all outputs are just

normally connected.

PLC program layout


43

5.5.2 Input and output handling

All the analogue inputs get converted to metric values before they get used

in the program. This is done by running a conversion function block every

time after the inputs are read and before the main program gets activated

(Figure 49). All these converted values are then stored in the

“PC_Variables” GVL, since all of these values are read by the PC. The con-

version values are as follows:

Brake temperature: o Raw input values: 0 – 65535

o Sensor range: 0°C – 300°C

o Conversion: 1 bit = 0.004578°C

Measured speed: o Raw input values: 1 increment = 0.01 Hz

o Slits / rotation : 5000

o Conversion: 1 bit = 1/8333.33 rpm

Measured current: o Raw input values: 0 – 65535

o Calibration: 1.2 A = 4245 raw input value

o Conversion: 1 bit = 0.00028267 A

Brake power

Current (inverter) o Raw input values: 1 increment = 0.01A

o Conversion: 1bit = 0.01 A

I/O handling in the PLC program


44

All of the variables that are linked to the physical outputs, are stored in the

“I_O” GVL. However, these variables do not get used during the main pro-

gram. For each output in the “I_O” GVL, there is an identical variable in

the “flags” GVL. The variables in this GVL are not linked with physical

outputs, though these are accessed during the main program. Only in the

last step of the main program, the values from the “flags” variables are

transferred to the corresponding values of the “I_O” GVL, with extra safe

logic added. This step is shown in Figure 49 at the “transferring digital out-

puts” step. The reason for this is to be able to have full control over the

outputs, and to be able to force them to the safe state at any given moment.

Figure 50 shows an example used in the program. The variables “boRo-

tateCW_K31” and “boRotateCCW_K32” are read from the “flags” GVL.

Because of the electrical layout, contactors K31 and K32 should never be

active at the same time since this would cause a major short-circuit. In order

to prevent this, extra safety measures are added in transferring the “flag”

value to the “I_O” value. By adding a negating contact of the other contac-

tor, one contact can never be active at the same time as the other. After this

the emergency stop variable is also added, so the emergency stop always

has the highest priority. This way, when the emergency stop is pressed,

“bNotEmergencyStop” will block the circuit (Figure 50) so bo_K31 and

bo_K32 can never get a Boolean “1”. By using this kind of structure

Link between the flag variable and the linked I_O variable.

5.6 Connection- and E-stop monitoring

5.6.1 E-stop monitoring

The main goal of adding the PLC was to improve the safety for when the

connection between the PC and motor was lost. An emergency stop bit has

been added in the program. When this bit is Boolean 0 the emergency stop

is active. The emergency stop is activated when at least one of the next

events occur:

The emergency stop is pressed

The current measured by the sensor or the drive exceeds 6A during five

seconds.

The connection between the PC and the PLC is lost

The brake temperature is over 45°C

When the emergency stop is active and none of the above event occur, it

takes 3 seconds for the emergency stop to reset. This is done to prevent the

emergency stop to activate too frequently.


45

5.6.2 Connection monitoring

In order to be able to detect if the connection is lost, every 50 ms the PC

writes a Boolean 1 in variable “bPoll”. This bit will reset an off-delay timer

so the variable “bConnectionActive” will stay active. The very next step in

the code is that “bPoll” is reset. This way, when the connection is lost, the

timer will not be reset, so “bConnectionActive” will be reset. Figure 51

shows this process.

When the connection is lost, the power to the drive and main 3-phase power

supply will cut off after 5 minutes. This delay has been added so the drive

will not lose power every time the PC crashes or the Ethernet cable is acci-

dently removed for a few seconds.

Connection monitoring

5.7 Datalogger

When a measurement is started, all the measured data has to be stored. The

datalogger saves all the measured data in an array (Table 1). This array has

one column for each variable to be measured, and an array containing the

timestamp of the sample. Every sample, an extra row is made and data is

stored in this row. In order to maintain a constant sample rate, the datalogger

runs completely separate from the main program, by using a separate PLC

task. This task is forced to run faster and given a higher priority than the

main program. A timer is added in the datalogger, giving pulses on at

constant rate. Every time a pulse is generated all the analog inputs are read,

and the values are stored in the array. The speed of these pulses (sample

rate) can be modified.

Speed

(rpm)

Current

(A)

Inverter

current

(A)

Brake

temperature

(°C)

Brake

power

(N)

Timestamp

(ms)

Sample 1

Sample 2

....

Sample n

Table 1 Array used for storing the measured data


46

5.8 Program selection

The selection of the starting mode is done by a separate function block

(“Program selector”). A number is sent by the PC, representing a selected

starting mode (e.g. 1 = direct start). Corresponding to this number, the func-

tion block for the selected starting mode is loaded.

Every function block for a starting mode has an input for starting the meas-

urement, and returns whether or not the measurement is busy. If any of the

modes is doing the measurement, none of the other modes can be started.

Also, the emergency stop is added in the logic, so that when the emergency

stop is active, the motor can never be started. The motor can only be started

when all the other modes signal that they are completed, the emergency stop

is not active and the start button is clicked on the PC.

5.8.1 Direct start

The direct start mode is executed by using a sequential flow chart function

block. When this function block is loaded, the program waits in the “Init”

step. Here all the contactors are reset and the function block signals that it

is completed and ready to start. Once the start signal is given (5.6), the con-

tactors are prepared, which means the motor gets connected in delta, the

direction gets chosen and only one contactor is left to start the motor. When

this is done, the datalogger is started and the final contactor is closed starting

the motor. After 3 seconds the contactor is opened again, and the motor is

stopped by using the brake. When the motor is stopped all the contactors

are opened again and the “Init” step is activated again.

SFC used for the direct starting mode


47

5.8.2 Star-delta start

Just as for the direct start, the star-delta mode also uses the sequential flow

chart. It works in the same way as the direct start, only now the motor is

first placed in star configuration and is then started. When the motor is at

nominal speed the star configuration is opened and the motor is placed in

delta configuration. A short delay is placed during this transfer in order to

prevent short circuits. When the measurement is done, the motor is uncou-

pled and braked.

SFC for the star-delta starting mode

5.8.3 Soft starter start

This starting mode uses the same SFC as the direct start (Figure 52). It takes

the exact same steps, only now the motor is not connected to directly to the

power, but to the soft starter.

5.8.4 Frequency converter start

The last starting mode is the start by using the frequency converter. When

this mode is selected the drive is connected to the motor. Just like the pre-

vious starting modes this also uses an SFC. The motor is started by using a

function block made for controlling the motor (5.8.6). This function block

is activated in the SFC, and given start – and stop commands. Note that the

brake is not used in this SFC, as the drive can slow down the motor itself.


48

5.8.5 Motor characteristic

This mode will be used to measure the torque-slip characteristic of the mo-

tor (2.2.3). In order to accomplish this, the motor is started in delta config-

uration with the soft starter. When the motor is running, the soft starter is

bridged so the motor is now directly coupled to the net. From this moment

the datalogger is started, and the brake applies full force to the motor. Be-

cause of this the motor will gradually slow down until it is completely

stopped. When the motor stopped, the motor is disconnected, the brake re-

leases and the datalogger stops.

5.8.6 Drive control (manual mode)

Because the drive uses PROFINET to communicate, a separate function

block (Figure 54) is made. Inside, various tasks are executed:

The emergency stop is connected to bit 2 of the control word. When this

bit is reset, the drive will make the motor stop very fast (0.5s).

All the contactors needed for the drive to operated are activated

The start and stop are connected to bit 0 of the control word. The code

that handles the stop is executed after the code for the start. This way

the stop always has priority to the start.

In manual mode, this block allows the speed and the direction of the

motor to be changed.

The “active” output is active when bit 1 of the status word is Boolean

1. This bit tells whether or not the motor is active.

The “complete” output is active when bit 1 of the status word is 0.

Function block to control the inverter.


49

6 PC PROGRAM

6.1 Existing

In 2012 Vincent Peerlinck had already written a major part of the program,

including the “simoclasses”[14]. He also prepared an interface for the meas-

urements, but it was lacking communication and still needed some improve-

ment.

6.2 PLC communication

To be able to send the data from the PLC to the PC, some way of commu-

nication has to be provided. Since the new system has to function for an-

other 20 years, this has to be a uniform and simple. Because every PC now

has at least standard 1 Ethernet port, and the CX9020 controller has it as

well, the communication will happen through an Ethernet connection. This

way the connection remains very simple by using just 1 Ethernet cable.

6.2.1 TwinCAT ADS

To allow the user program (C#) to communicate with the TwinCAT pro-

gram in the CX9020 controller, the TwinCAT ADS interface must be used.

The Automation Device Specification (ADS) is a device- and fieldbus-in-

dependent interface [16], which in this case will be used with the TCP/IP

protocol.

The .NET component of ADS is used in

C# (figure 51). It’s done by importing the

TwinCAT.Ads namespace into visual stu-

dio. This allows communication with the

TwinCAT message router that has to be

installed on the PC. This router is neces-

sary for translating the ADS messages and

sending it to the right devices on the net-

work through the TCP/IP (Ethernet) port

of the PC. On the other side of the Ether-

net cable is the CX9020 controller, which

is also fitted with the message router so

the messages can access the PLC program

in the TwinCAT 3 runtime.

ADS structure


50

TwinCAT ADS uses the client/server-principle on TCP, with the PC as the

client and the CX9020 controller as the server. This means that the PC al-

ways accesses the controller and not vice versa. The structure of the mes-

sages sent by the ADS interface is shown in Figure 52. This ADS data

packet consists of various parts:

AMS Net ID: This is the unique device address in the ADS network. It

is an address apart from the IP-address. The ADS routers will create a

link between these two addresses

ADS Port: The port that will be used for the data to pass through. This

is standard port 851.

Index group: This contains the location of the group of variables (e.g.

GVL) that has the desired variables to be accessed.

Index offset: The location of the variable in the group.

ADS Data: Contains the type of service (read, write, connect, ..) and

the data to be transmitted between the devices.

All this data is preceded by the standard TCP header and the IP-header.

Lastly there are the acknowledge bits (SA, DA) and the CRC code (“cyclic

redundancy check”).

ADS message


51

6.2.2 Class structure

Figure 57 shows the class structure used in the PC program. A separate class

is made that handles the communication with the PLC

(“PLC_ADS_Communication.cs”). This is done so that higher classes

(forms) can communicate easily with the PLC by simply calling methods

from this class. The class “MeasuredData.cs” is the class for the user form

containing all the data, charts and controls for the PLC.

Class structure in the C# program

6.2.3 Connecting to the PLC

The first thing to happen is to connect the PC to the PLC. This is done by

the code shown below, which is run by the PLC_ADS_Communication

class. The PC is assigned as an ADS client, and connect to the device with

a specified address and port. This address and port can be changed in the

program, and is stored so it keeps this the next time the program starts.

public void connectAdsClient()

{

adsClient = new TcAdsClient();

try

{

AmsNetId address = new AmsNetId(amsNetID);

adsClient.Connect(address, port);

}

catch (Exception e)

{}

}

6.2.4 Variable handles

To access variables in the PLC, the C# program needs to use “variable han-

dles”. These variable handles are variables that contain information about

the location of the variables handle in the PLC. As an example the declara-

tion of the variable for the program mode in the PLC is shown below. It is

important to note that the variable “hModeProgram” does not directly con-

tain the data of the PLC variables. It is only used for accessing the variable.

private int hModeProgram;

hModeProgram=adsClient.CreateVariableHandle("PC_Variables.

intModeProgram");


52

Next is shown how the value in the PLC is changed by using this variable

handle. The parameter “mode” has a number representing the number of the

selected starting mode.

public void ChangeProgramMode(Int16 mode)

{

adsClient.WriteAny(hModeProgram, mode);

}

Reading a variables is done in almost the same way. This is an example

where the speed of the motor is read from the PLC. The variable “hSpeed”

is the variable handle for the variable in the PLC.

public UInt16 getSpeed()

{

Return Convert.ToUInt16(adsClient.ReadAny(hSpeed

, typeof(double)));

}

6.2.5 PLC-connection monitoring

As explained in 5.6.2, the connection is monitored by constantly setting a

bit in the PLC. This is done by running a separate thread in the class of the

measured data form. This thread is started when the program opens, and

constantly writes the necessary bit in the PLC. It also reads information

about the emergency stop and PROFINET connection state. If it can’t read

this info, it means that the connection between the PC and the PLC is lost.

Whenever this happens, an error message is shown and the complete user

interface gets disabled. Now the thread will try to connect to the PC again

every 3 seconds. Also the bottom status bar will show that the PLC is dis-

connected.

6.2.6 Retrieving measured data

When the user starts a measurement, the program freezes while the motor

is running to prevent the user from clicking wrong things during the meas-

urement. When the PLC finishes the measurement, the PC gets notified and

reads the array containing all the measured data (chapter 5.7). This array is

sent through ADS interface as a data stream. The PLC communication class

reads this class and restores it back into an array of a “struct”. This struct is

created by making a new variable of the class “PLCDataPoint” shown be-

low

public class PLCDataPoint

{

public double nSpeed;

public double nCurrent;

public double nCurrentInverter;

public double nBrakeTemp;

public double nBrakePower;

public double nAcceleration;

public double dSlip;

public double nTimeStamp;

}


53

This class contains a variable for each measured parameter by the PLC, in

addition to the extra variables for calculation the slip and acceleration.

Before reading the stream, the length of the stream has to be provided. This

is calculated by following equation.

𝐿𝑒𝑛𝑔𝑡ℎ = 𝑁 ∗ 8 ∗ 5

(9)

Here, N = the amount of measurements taken by the PLC. Each measure-

ment has five values, with each value being an 8-byte double. Multiplying

all these numbers results in the expected length of the stream in bytes. Next

step is to read the stream. The stream starts by reading the first 8 bytes (1st

value of the 1st measurement) and writing the resulting value in correspond-

ing variable of the PLCDataPoint. After these 8 bytes, the next 8 bytes are

read and again written in the next variable. After 5x8 bytes, the variable of

the PLCDataPoint contains all the data from the 1st measurement and is

stored as the first element in an array of PLCDataPoints.

The acceleration is calculated by subtracting the current measured speed

from the speed of the previous sample. To reduce the noise of this calcula-

tion, it averaged by adding four previous acceleration to each other and di-

viding it by four (equation 10). The same noise reduction is done for the

measured braking power.

𝛼𝑎𝑣 =

𝛼𝑠 + 𝛼𝑠−1 + 𝛼𝑠−2 + 𝛼𝑠−3

4

(10)

At the same time of reading the value of the speed, the slip is calculated by

equation 11)

𝑠 =𝑛𝑠𝑦𝑛𝑐ℎ𝑟 − 𝑛𝑚𝑒𝑎𝑠

𝑛𝑠𝑦𝑛𝑐ℎ𝑟

(11)

After all the measurements are read and stored, the array of PLCDataPoints

is returned to the “measured data” form, where it will be used to put in

charts.

6.2.7 Updating gauges

When the user is in manual control mode, a real time feedback from varia-

bles to the user is required. To achieve this an extra thread is used, which

constantly reads the values from the PLC and runs separately so the main

program doesn’t freeze.


54

6.3 Layout

The main layout of the program is shown in Figure 58. It consists of differ-

ent parts:

1: The window for the laboratory. This has not been part of this thesis.

For more information please refer to the thesis of Vincent Peerlinck [14]

2: This window is used for all the measurements and control of the mo-

tor.

o a: This part contains the control for the selected starting

mode. Depending on which starting mode settings can be

made here.

o b: Here the student can choose which starting mode has to

be used.

o c: After measurements are made, they are shown in this chart

area.

o d: Because various parameters are measure, the user can

choose which chart needs to be shown here.

3: Here the status of the PLC, inverter and brake are shown. When an

error occurs it is shown here which kind of error this is.

Layout of the main program


55

6.3.1 Starting modes

The 4 different starting modes (direct start, start-delta start, soft starter, and

inverter) and the characteristic mode all have the same layout. By clicking

on the corresponding tab page, a starting mode is selected. To start the meas-

urement the user just has to press the “start” button. Only for the inverter

start an extra parameter is added (Figure 59). The user can modify the ramp-

up time from the motor ranging from 0.7 seconds to 2.8 seconds.

Inverter start tab page

6.3.2 Manual control

If the user selects the manual control, he gets control over various parame-

ters in the setup. Every parameter has received its own colour in order to

maintain a better overview (Figure 60). First of all the user can control the

rotation speed (green) of the motor by rotating the green knob. The user

then gets feedback of the motor speed by both a digital and an analogue

gauge. Secondly, the user also can change the braking force of the brake

(blue) by rotating the blue knob. The braking force is shown in Nm and

percentage of the maximum force. Furthermore, the brake temperature is

shown (red). When this value exceeds 50°C, the brake will be disabled.

Next, the user also get feedback from the current that is flowing through the

engine, measured by the drive. Lastly the rotation direction can be changed

and the ramp-up time can be modified.


56

Manual control screen

6.3.3 Charts

In order to be able to show the user the data that has been measured, charts

are used. Three different charts are used: the “start-up chart”, “Acceleration

chart” and the “characteristic chart”.

6.3.4 Start-up chart

The start-up chart shows the user the progression of the start-up current. It

will draw current of all 4 different starting types, with each its own unique

colour. These colours are the same in the other charts as well. Figure 61

shows this chart, with the current of the direct start highlighted. The pro-

gram will highlight the line of the starting mode that is currently selected.

When the user goes to the “star-delta” starting mode, the yellow line of start-

delta will be highlighted etc. . Also, the user has the option to clear all the

starting modes so the chart will be empty.

Start-up chart


57

6.3.5 Acceleration chart

This chart shows both the acceleration and the speed of the motor. The same

colours as in the start-up chart are used in order to make it easier. The speed

is always darker then the acceleration, but still has the same colour. De-

pending on the selected starting mode, the corresponding curves are high-

lighted. Furthermore, the user can also choose to only show the acceleration

or only the speed chart. Figure 62 shows the chart for the inverter start

mode.

Acceleration chart

6.3.6 Characteristics chart

When the user starts the motor in motor characteristics mode, the torque-

speed characteristic is measured and shown (Figure 63).

Characteristic chart

6.3.7 Status bar

The status bar is located on the bottom of the screen, and gives a small over-

view of the status of the setup (Figure 64). It shows whether or not the PLC

is connected, and the current AMS Net ID that is being used. It also shows

if the inverter is disconnecting, connecting and connected. Lastly it also

gives a sign when the brake is overheated.

Status bar


58

7 CONCLUSION

It can be concluded that the program works and is ready for students to use.

The old computer and program are replaced by a brand new PC and pro-

gram. This program has now been improved and finished as well. The hard-

ware located on the system has also been upgraded so the setup can go on

for another 20 years.

The new setup is equipped with a brand new drive, and Beckhoff CX9020

PLC. This PLC is fitted with all the necessary I/O terminals so the old I/O

cards of the old system are removed. Next the old ACS600 drive has been

removed and replaced by a new ABB ACS 355 drive. These new compo-

nents made it possible to upgrade the communication system. Now the com-

munication between the PC and PLC is realized by using one simple Ether-

net connection by the use of the TwinCAT ADS interface. Furthermore, the

communication between the PLC and the drive now also happens through

an Ethernet connection by using PROFINET. Resulting from all of this is a

simpler, yet safer system. Thanks to the new controller, the system can al-

ways come to a safe stop when the PC crashes or any of the connections is

lost. This has resulted in a more student proof setup.

The software on the PC is now compatible with Windows 7, since it is a

completely new program. A big part of the program has already been made

previously, but has now been completed by improving the layout and adding

communication with the PLC. This communication has been realized by

using the TwinCAT ADS interface.

With the completed setup the students are now able to get a better vision of

the difference between the starting modes of an ASM. By adding new tech-

nology in the hardware, students can also get a first touch of PROFINET

communication and PLC’s.

Completed motor test unit


59

SOURCES

[1] “Embedded PC for building automation,” 2013. [Online]. Available:

http://www.instrumentation.co.za/45356n.

[2] MpowerUK, “Electric Drives - AC Motors (Description and Applications).”

[Online]. Available: http://www.mpoweruk.com/motorsac.htm.

[3] G. Vandensande, “Elektrische machines.” .

[4] Meggar, “Squirrel cage rotor.” [Online]. Available:

http://en.wikipedia.org/wiki/Induction_motor#/media/File:Squirrel_cage.jpg.

[5] J. Rees, M. Kjellberg, and S. Kling, “Softstarter Handbook,” p. 92, 2010.

[6] R. Naukkarinen, “Drive Module Testing Method Comparison for Drive Service

Workshop,” 2012.

[7] B. Akin and N. Garg, “Scalar ( V / f ) Control of 3-Phase Induction Motors,”

2013.

[8] OGURA Industrial corp., “Electromagnetic clutches and brakes.” [Online].

Available: http://www.ogura-

clutch.com/products/industrial/howtheywork/electromagnetic-particle-

brake.html.

[9] Mandee Liberty & Vikram Phadke, “Encoders Basic Training.” .

[10] Pepperl & Fuchs, “Incremental Encoder Output Signal Overview,” pp. 1–3.

[11] E. a G. L, “Technical bulletin,” vol. 1, no. 909, p. 2, 2003.

[12] PROFIBUS & PROFINET International (PI), “PROFINET The Leading

Industrial Ethernet Standard.” [Online]. Available:

http://www.profibus.com/technology/profinet/.

[13] Osmo vuotila, “Physical and Electrical Planning of 3-phase AC-Engine

Measuring Device,” HAMK, 2000.

[14] V. Peerlinck, “Upgrade computer program for engine,” HAMK University Of

Applied Sciences, 2012.

[15] Beckhoff, “CX 9020 Manual.” pp. 1–48, 2015.

[16] Beckhoff, “TwinCAT ADS.” [Online]. Available:

infosys.beckhoff.com/english.php?content=../content/1033/tcadsdeviceplc/html/t

cadsdeviceplc_intro.htm&id=.


Appendix 1

HARDWARE LIST

Devicename Manufacturer Type Properties Motor ABB M2AA 90 L ; 3GAA 092 002 3-phase , 4 poles, 1,5 kW

Encoder Kübler 8.5820.1541.5000 5000 pulses/revolution

Brake Lenze 04 Magnetic powderbrake, 40Nm

Brake amplifier P.Poukkula Oy 0-10VDC to 0-24V DC 1A

PT-100 sensor 0-300°C

PT-100 converter Datexel DAT 201 3W-0-10V-PT100-0-300 0-300°C , 0-10VDC output

Current meter Carlo Gavazzi A 82-10-50 Maximum 50A AC

Frequency converter ABB ACS355-03E-05A6-4+k466(+acs-cp-A) With FENA11 adapter and controlpanel

Power supply Murrelekronik MCS5-230/24 24VDC, 5A, regulated

Loadcell Gefran TC-K1C-F-S 0-100kg

Loadcell amplifier Gefran CIR-N-2-N-O 3mV/V

Relay Moeller DIL EM-01-G 3-phase, 24V DC signal

Relay Schrack MT321024 3 x switches, 24V DC signal

Relay socket Schrack MR78750

PLC controller Beckhoff CX9020-0110-M930 + 2 x RJ-45 PROFINET CONTROLLER

PLC Encoder interface Beckhoff EL5101 RS422 inputs

PLC Bus coupler Beckhoff BK1250 E-bus to K-bus

PLC DI Beckhoff KL1408 8xDI

PLC DO Beckhoff KL2408 8xDO

PLC AI Beckhoff KL3064 4 x AI, 0-10VDC

PLC AI Beckhoff KL3102 4 x AI, 0-20mA

PLC AI Beckhoff KL3112 2 x AI, -10-10V DC

PLC AO Beckhoff KL4002 4 x AO, 0-10VDC

PLC End terminal Beckhoff KL9010


Appendix 2

PLC IO TABLE

Controller

Beckhoff CX9020-0110-M930

Type Address Description Device Signal

EN Port 1 Ethernet PC

EN Port 2 Ethernet

PN Port 1 PROFInet RT Inverter

PN Port 2 PROFInet RT

Encoder interface

Beckhoff EL5101


DI A Kübler 0-5VDC

DI A/ Kübler 0-5VDC

DI B Kübler 0-5VDC

DI B/ Kübler 0-5VDC

DI C Kübler 0-5VDC

DI C/ Kübler 0-5VDC

Out 24V Kübler 24VDC

Out 0V Kübler 0VDC

Binary Inputs

Beckhoff KL1408


DI 1 Fuse Fused terminal block 0/24 VDC



DI 4 -

DI 5 -

DI 6 -

DI 7 -

DI 8 E-stop Button 0/24VDC

Binary Outputs

Beckhoff KL2408


DO 1 K21 DILEM-01-G 0/24 VDC












DO 12

DO 13

DO 14

DO 15

DO 16

Analog Inputs

Beckhoff KL3064


AI 0 Brake temp. PT-100 0-10 VDC

AI 2 0-10 VDC

AI 4 Brake power Gefran 0-10 VDC

AI 6 0-10 VDC

Analog Inputs

Beckhoff KL3112


AI 8

AI 10

AI 12 Current Carlo Gavazzi 0-20mA

AI 14

Analog Inputs

Beckhoff KL3102


AI 16

AI 18

AI 20 Current Carlo Gavazzi -10-10V

AI 22

Analog Outputs

Beckhoff KL4002


AO 0

AO 2 0-10 VDC

AO 4 Brake Amplifier 0-10 VDC

AO 6 0-10 VDC


Appendix 3

ACS355 MODIFIED PARAMETERS

Number Name Value Description

9909 Motor nom. Power 1.8 kW

9908 Motor nom. Speed 1420 rpm

9906 Motor nom. Curr 3.5A

9802 Comm. Prot. Sel. EXT FBA Communication through FENA 01

5102 Protocol 10 ProfiDrive

5104 IP Configuration 0 Static IP

5105 192

5106 168

5107 1

5108 4

5109 Subnet CIDR 24 255.255.255.0

5110 GW Address 1 192

5111 GW Address 2 168

5112 GW Address 3 1

5113 GW Address 4 1

5501 FBA Data out 1 1 Control word

5502 FBA Data out 2 2 REF1

5503 FBA Data out 3 2202 Parameter 2202 ”Acc. Time 1” is remotely

modified this way.

5401 FBA Data in 1 4 Status word

5402 FBA Data in 2 5 Actual Value 1

5403 FBA Data in 3 104 Current

5404 FBA Data in 4 102 Speed

5127 FBA Par Refresh REFRESH Restarts the FENA 01 module to apply params.

3401 Signal 1 Param SPEED The speed gets shown on the display

2601 Flux opt. Enable ON Activates the flux optimization function

2602 Flux braking FULL Activates the flux braking function

2606 Switching Freq 16kHz

2609 Noise Smoothing Enable

2208 Emergency Dec. Time 0.5s

2203 Deceleration time 1 7.0s

2102 Stop function RAMP

1610 Display alarms YES

1609 Start Enable 2 COMM

1608 Start Enable 1 COMM

1604 Fault reset select Start/Stop

1601 Run enable COMM

1103 REF1 Select COMM

1002 EXT2 Commands COMM

1001 EXT1 Commands COMM

5127 FBA Par Refresh REFRESH Restarts the FENA 01 module to apply params.

!!! Remember to put the drive in REMOTE control mode by pressing the ”Loc/rem”

button. The display mentions ”REM” in the top left corner when it is in remote control

mode.


Appendix 4

ELECTRICAL SCHEMATICS

Blad

Blad

Projectsjabloon met IEC-coderingsstructuur

Bew.

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELEC3F DISTRIBUTION

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

2

4

13/05/2015 HAMK University of Appliedsciences

1

2

=

Naam

5

ABB ACS355 SOFTSTARTER

-1U0-L1 -L2 -L3 -N -PE

-PE:1

3

6

2

5

1

4

-K21/6.1

3

6

2

5

1

4

-K31/6.6

3

6

2

5

1

4

-K22/6.2

3

6

2

5

1

4

-K24/6.4

3

6

2

5

1

4

-K23/6.3

3

6

2

5

1

4

-K25/6.5

3

6

2

5

1

4

-K10/7.3

3

6

2

5

1

4

-K32

3

6

2

5

1

4

-K41/6.8

3

6

2

5

1

4

-K42/7.1

W1V1U1

W2V2U2

-1M33~M

-U1 -V1 -W1

-U2 -V2 -W2

-U1 -V1 -W1

-U2 -V2 -W2

-X2 1 2 3 4

-X3 1 2 3

-X3 4 5 6

Blad

Blad


Bew.

1

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELEC1F DISTRIBUTION

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

3

4


2

2

=

Naam

5

-2U0-L1 -N -PE

8-X2 7 9

1

2

-M2M1~

1

2

-M3M1~

-X4 1

-X4 2-X4 4

-X4 3

24

21

-K90/7.2

1

2

-M1M1~

1

2

-M4M1~

11

12

-K90/7.2

1 2PE 1 2PE 1 2PE 1 2PE

-X2 5 6

1

3

2

4

5

-PE

-PE

24VDC / 3.0

0V / 3.2

NL1 PE

0VDC

Blad

Blad


Bew.

2

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELEC24VDC

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

4

4


3

2

=

Naam

5

-X1 2

-X1 4

5

8

-X1 9

21-X1 22

24-X1 25 26 27 28 29

-PE

24VDC2.5

24V_Pow

erA

mp

/11.1

24V_PLC

/

24V_ESTO

P/

5.8

24V_TRAN

SD

UCER

/10.2

24V_F2

/5.2

24V_F1

/5.1

24V_PT100

/8.3

24V_CU

RREN

TM

ETER

/9.1

0V

/2.5

0V_PO

WERAM

P/

11.1

0V_RELAY

/

0V_PLC

/

0V_PT100

/8.3

0V_TRAN

SD

UCER

/10.3

0V_CU

RREN

TM

ETER

/9.3

Blad

Blad


Bew.

3

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELECPLC_KL5101

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

5

4


4

2

=

Naam

5

1

A

=ELEC+-ENCODER:GREEN

-EL5101

8'

S

6'

+

7'

-

2'

+

3'

-

2

B

3

C

4

G1

5

A'

6

B'

7

C'

8

G2

1'

UE

5'

U0

4'

I1

13142018161917-X1 15

ENCODER

GREEN GREY BLUE YELLOW PINK RED BROWN BU-RD WHITE GY-PK

Blad

Blad


Bew.

4

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELECPLC_DI_KL1408

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

6

4


5

2

=

Naam

5

-26U1

1 2 3 4 5 6 7 8

11

12

-Q1

EStop

24V_F1

/3.1

24V_F2

/3.1

24V_ESTO

P/

3.1

Blad

Blad


Bew.

5

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELECPLC_DO1_KL2408

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

7

4


6

2

=

Naam

5

-?U1

A1

A2

-K21

41 /1.3

52 /1.3

63 /1.3

2122 /6.3

2221 /6.5

A1

A2

-K22

41 /1.4

52 /1.4

63 /1.4

A1

A2

-K23

41 /1.4

52 /1.4

63 /1.4

2221 /6.1

2122 /6.5

A1

A2

-K24

41 /1.5

52 /1.5

63 /1.5

A1

A2

-K25

41 /1.5

52 /1.5

63 /1.5

2122 /6.1

2221 /6.3

A1

A2

-K31

41 /1.3

52 /1.3

63 /1.3

1211 /6.7

A1

A2

-K32

41 /1.4

52 /1.4

63 /1.4

1211 /6.6

A1

A2

-K41

41 /1.4

52 /1.4

63 /1.4

1211 /7.1

22

21

-K25/6.5

22

21

-K21/6.1

22

21

-K23/6.3

11

12

-K32

11

12

-K31/6.6

11

12

-K42/7.1

21

22

-K23/6.3

21

22

-K25/6.5

21

22

-K21/6.1

1 2 3 4 5 6 7 8

-0V/7.1

Blad

Blad


Bew.

6

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELECPLC_DO2_KL2408

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

8

4


7

2

=

Naam

5

-?U1

A1

A2

-K42

41 /1.5

52 /1.5

63 /1.5

1211 /6.8

A1

A2

-K90

1211 /2.2

2124 /2.2

A1

A2

-K10

41 /1.3

52 /1.3

63 /1.3

11

12

-K41/6.8

1 2 3 4 5 6 7 8

-0V/6.1

Blad

Blad


Bew.

7

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELECPLC_AI_KL3064

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

9

4


8

2

=

Naam

5

0-10V

-U3/9.0

/10.0

1 2 3 4 5 6 7 8

PT100 converterDAT 201

F

G

H

A

B

DPT100

-X1 6

24V_PT100 / 3.1

0V_PT100

/3.3

Blad

Blad


Bew.

8

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELECPLC_AI_KL3112

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

10

4


9

2

=

Naam

5

0..20mA

-U3/8.0

/10.0

1 2 3 4 5 6 7 8

-8U1

-X1 3

Yellow Black

Red

24V_CU

RREN

TM

ETER

/3.1

0V_CU

RREN

TM

ETER

/3.3

Blad

Blad


Bew.

9

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELECPLC_AI_KL3102

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

11

4


10

2

=

Naam

5

-U3/8.0/9.0

1 2 3 4 5 6 7 8

-X1 7

Transducer

Red White Green Yellow

Red Black White Green Blue Orange Screen

Loadcell

Red Black White Green Blue Orange Screen

24V_TRAN

SD

UCER

/3.1

0V_TRAN

SD

UCER

/3.3

Blad

Blad


Bew.

10

Oorspr

IEC_tpl001

HAMKKEVIN +

Datum

Datum

Vervangen door

ELECPLC_AO_KL4002

1

Wijziging

0 76

Gecontr

Vervanging van

8 93

11

4


11

2

=

Naam

5

-X1 11 12

-?U1

1 2 3 4 5 6 7 8

Poweramplifier

3 421

5 6

Brake1 2

24V_Pow

erA

mp

/3.0

0V_PO

WERAM

P/

3.2

Auteursrechtelijke overeenkomst

Ik/wij verlenen het wereldwijde auteursrecht voor de ingediende eindverhandeling:

Upgrade of the motor test unit

Richting: master in de industriële wetenschappen: energie-automatisering

Jaar: 2015

in alle mogelijke mediaformaten, - bestaande en in de toekomst te ontwikkelen - , aan de

Universiteit Hasselt.

Niet tegenstaand deze toekenning van het auteursrecht aan de Universiteit Hasselt

behoud ik als auteur het recht om de eindverhandeling, - in zijn geheel of gedeeltelijk -,

vrij te reproduceren, (her)publiceren of distribueren zonder de toelating te moeten

verkrijgen van de Universiteit Hasselt.

Ik bevestig dat de eindverhandeling mijn origineel werk is, en dat ik het recht heb om de

rechten te verlenen die in deze overeenkomst worden beschreven. Ik verklaar tevens dat

de eindverhandeling, naar mijn weten, het auteursrecht van anderen niet overtreedt.

Ik verklaar tevens dat ik voor het materiaal in de eindverhandeling dat beschermd wordt

door het auteursrecht, de nodige toelatingen heb verkregen zodat ik deze ook aan de

Universiteit Hasselt kan overdragen en dat dit duidelijk in de tekst en inhoud van de

eindverhandeling werd genotificeerd.

Universiteit Hasselt zal mij als auteur(s) van de eindverhandeling identificeren en zal geen

wijzigingen aanbrengen aan de eindverhandeling, uitgezonderd deze toegelaten door deze

overeenkomst.

Voor akkoord,

Geutjens, Kevin

Datum: 10/06/2015

2014•2015 faculteit industriËle … · upgrade of the motor test unit promotor : ing. eric...

Documents